What is ‘human factors’?

We’re all human. We all make mistakes and forget things. Our attention span is limited. We overlook key information when making decisions. We get distracted, bored, tired or preoccupied. We mishear and misunderstand.

These are as much a part of human life as breathing and sleeping. Human factors is concerned with understanding and managing the capabilities and limitations of people. It is the application of scientific knowledge and principles – as well as lessons learned from previous incidents and operational experience – to optimise health, safety, well-being, overall system performance and reliability.

Clearly, we can’t change the human condition, but we can design activities, plant, processes and procedures in such a way that takes into account human imperfections.

“Everyone can make errors no matter how well trained and motivated they are. Sometimes we are ‘set up’ by the system to fail.
The challenge is to develop error-tolerant systems and to prevent errors from occurring”

(Reducing Error and Influencing Behaviour, HSG48, HSE, 1999, p.18)

Human factors addresses what people are being asked to do (the Work and its characteristics), who is doing it (the People and their competence) and where they are working (the Organisation and its attributes).

The Work

Tasks should be designed in accordance with human factors principles to take into account the limitations and strengths of People. Matching the Work to the person will ensure that they are not overloaded and that the most effective contribution to the business results. Physical match includes the design of the whole workplace and working environment. Mental match involves the individual’s information and decision-making requirements, as well as their perception of the tasks and risks. Mismatches between the Work requirements and the capabilities of People increases the potential for human error.

The People

People have different attitudes, experiences, skills, habits and personalities. In the workplace, these individual differences can be strengths or weaknesses, depending on the Work. These characteristics of People may have a positive or a negative impact on the performance of Work. Some aspects of People are fixed, such as physical dimensions and personality, but others such as skills and attitudes may be changed or improved.

The Organisation

Factors relating to the Organisation have a significant influence on the behaviour of People. A key organisational factor is the culture, which outlines what is and what is not acceptable behaviour. Other factors include how work is planned and organised. These factors are often not under the control of People who are doing the Work. Many accidents are blamed on the actions or omissions of People directly involved in the Work. This response ignores fundamental failures within the design, management and decision-making functions of the Organisation.

Human factors offers the possibility for delivering the next step change in improved safety performance, as well as improving environmental, quality and business performance. Examples of factors relating to the Work, People and Organisation that are often-cited as causes in accidents are provided below. A more complete list of these Performance Influencing Factors is available.

Work factors

  • illogical design of equipment and instruments
  • constant disturbances and interruptions
  • missing or unclear instructions
  • poorly maintained equipment
  • high workload
  • noisy and unpleasant working conditions.

People factors

  • low skill and competence levels
  • tired staff
  • bored or disheartened staff
  • individual medical problems.

Organisation factors

  • poor work planning, leading to high work pressure
  • lack of safety systems and barriers
  • inadequate responses to previous incidents
  • management based on one-way communications
  • deficient co-ordination and responsibilities
  • poor management of health and safety
  • poor health and safety culture.

Human factors is about ensuring a good ‘fit’ between people, the equipment they use, the task they carry out and the environment in which they work. Effective use of human factors will make work safer, healthier and more productive.

A simple definition of human factors is: Making it easy for people to do the right thing (and hard to do the wrong thing). For more details of this approach to human factors, see my article on how we might influence the behaviour of Homer Simpson at work – and the factors that might influence whether he does the right thing.

Isn’t it just about people ‘taking more care’?

Telling people to take more care is not the answer. While it is reasonable to expect people to pay attention and take care, relying on this is not enough to control risks. Optimising human performance involves far more than taking disciplinary action against an individual. There are a range of measures which are more effective controls including design of the job and equipment, procedures, and training. This website will provide you with practical information to help you start to manage human factors.

“Failures arising from people other than those directly involved in operational or maintenance activities are important.
Managers’ and designers’ failures may lie hidden until they are triggered at some time in the future”

(Reducing Error and Influencing Behaviour, HSG48, HSE, 1999, p.18)

Human error and human performance

One of the areas where human factors can contribute is in preventing human errors (or reducing the likelihood of errors). If aspects of the Work, People and Organisation are not optimal, then we can expect a decline in human performance and an increase in human errors. But this does not mean that we should be focussing on the actions and decisions of front-line workers. In the past, incidents may have been attributed to human error, without further explanation. That approach is now less common, and it is generally appreciated that we need to look beyond human error as a cause. Investigations should attempt to understand how People are “set up to fail” by the design of equipment or systems of work. The human factors approach aims to set people up to succeed, by considering the wide range of factors that influence their actions and decisions, and by matching Work demands to the capabilities and limitations of People.

Human factors will help to address aspects of human performance such as the following:

  • Why do people make mistakes and other types of human errors? Are these random events, or can we identify factors that make them more likely? The prevention measures will depend on the exact type of human error.
  • Why do people break the rules? Did the person break the rule intentionally, or is it because they didn’t know about the rule? Perhaps the rule was unworkable in practice, or a person had competing demands on their time.
  • Why do people take risks? People tolerate different levels of risk and sometimes people change their behaviours in order to increase, or reduce, the perceived risk. Behavioural safety approaches aim to influence risk taking behaviours.
  • Why do accidents happen? Accidents are usually the result of a combination of contributory factors. Human factors approaches can help to better understand accidents that have occurred, and also help to prevent future events. In other words, human factors can help to identify what went wrong, and predict what could go wrong.

It’s important to note that although human performance issues may contribute to incidents; human actions and decisions prevent or correct dangerous situations on a daily basis. People are generally adaptable, and with experience, can solve highly complex problems, often with limited information. The challenge for human factors is to maximise these positives, whilst also managing the limitations of people.

Where do human factors professionals work?

Human factors professionals work in a wide range of industries including aviation, nuclear, healthcare, mining, rail, agriculture, finance, oil and gas and so on. Others work in research and academia, often working with industry partners to undertake research that has practical application. You will also find human factors professionals working for various Regulators, particularly those who regulate health and safety.

The advantage of choosing a career in human factors is that you learn transferable skills that can be applied to any industry.

In my career, I have held positions in research, consultancy, regulation and industry, and I have worked in all of the industries listed above. I’ve designed the cockpit displays for a helicopter, undertaken risk assessments 1km underground in coal mines, interviewed train drivers in the cab whilst travelling through the Eurotunnel, assessed pilot communications in the cockpit of commercial airlines, audited many offshore installations from small drilling rigs to large production platforms, and assessed control rooms on nuclear power plants. I can’t think of a more interesting way to have spent the last 30 years!

For more information about the various career options, and to read about the work of several human factors professionals, see this Careers Guide from the UK Chartered Institute of Ergonomics and Human Factors (CIEHF).

EHF Careers Guide - humanfactors101.com

“As an ergonomist or human factors specialist, you’ll study people and the products, tools and equipment they use at home, at play and at work, the places in which they live and work, the transport they use to get around, and the systems they interact with that keep day-to-day life functioning properly.

If you’re looking for a comfortable 9 to 5 office job, where you know exactly what you’re going to be doing every day, then this isn’t for you! As a practising ergonomist and human factors professional you could find yourself outside in all weathers, working nights, working away from home but you’ll see and experience things that you’ll always remember”.

Ergonomics & Human Factors Careers Guide, UK Chartered Institute of Ergonomics and Human Factors (CIEHF)

What are human factors approaches?

In order to identify human factors issues and address the capabilities and limitations of people, there are several approaches that can be used. These approaches usually aim to accomplish one or more of the following:

  1. Identify the characteristics of the people who will be working in the system, or using a product
  2. Identify the requirements of the work to be undertaken
  3. Evaluate the nature of work, a system or a product.

When we can describe the characteristics of the people and identify the nature of what we are asking them to do, we are in a good position to design work, a product or a system that matches the two together. This will result in the design of a usable product or system; a design that will be better for the user and for the organisation in which they work.

The methods used in human factors may include:

Checklists: these allow a comparison of certain attributes of existing or planned systems with acceptable values. They are useful for quick evaluations of a wide range of attributes.

Questionnaires and surveys: These are a good option for gathering information from a wide range of people. They can be a very efficient way of gathering factual information such as age, gender, educational background, years of experience and skills – as well as obtaining opinions. Questions can be a combination of ‘closed’ (e.g. using Yes/No responses, or a scale from 1 to 5) and ‘open’, where the response can be free text (i.e. respondents write in their own words).

Observation: the analyst simply observes people doing various tasks. As the observer is often not an expert in the work that they are observing, they may need to ask people what they’re doing (and why they’re doing it). If questions from an observer could be a distraction, they can be asked afterwards, perhaps reviewing video footage of the work being completed.

Usability testing: A user is given a set of tasks to accomplish, or a product to evaluate and the facilitator observes the user, records issues and asks for feedback. This approach is often used to test the usability of websites and other interfaces. Care must be taken not to influence or prime the user.

Incident investigation: When injuries or property damage occurs, investigations aim to identify and classify the various causes that combined to lead to an incident. There are a number of formal root cause investigation techniques available, many of these require the investigators to have well-developed technical and non-technical skills. They usually involve a combination of checklists, questionnaires and interviews; as well as review of the worksite and documentation.

Task analysis: A range of methods that identify and structure the important elements of a task. These approaches describe what people do, what they need to know, and what people or equipment they interact with. Ideally, information is gathered from the people who actually perform the tasks, gained from observation at the place of work, or in an interview.

Link analysis: As most work doesn’t happen in isolation, link analysis aims to identify and assess the important associations and relationships between different elements such as other people, displays, controls and other equipment. This method looks at how often and for how long there is a ‘link’ between two or more elements.

Walk-through / Talk-through: A walk-through consists of having people walk through a certain set of tasks, either at the workplace or on a simulator. A trained observer watches the actions, records timings, and notes potential human factors issues. Walk-throughs may be recorded for later review. A variation of this approach is the Talk-through, where the person carrying out the work describes what they are doing and why.

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